// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/cert/jwk_serializer.h"

#include "base/base64url.h"
#include "base/values.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace net {

namespace {

    // This is the ASN.1 prefix for a P-256 public key. Specifically it's:
    // SEQUENCE
    //   SEQUENCE
    //     OID id-ecPublicKey
    //     OID prime256v1
    //   BIT STRING, length 66, 0 trailing bits: 0x04
    //
    // The 0x04 in the BIT STRING is the prefix for an uncompressed, X9.62
    // public key. Following that are the two field elements as 32-byte,
    // big-endian numbers, as required by the Channel ID.
    static const unsigned char kP256SpkiPrefix[] = {
        0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86,
        0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x08, 0x2a,
        0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03,
        0x42, 0x00, 0x04
    };
    static const unsigned int kEcCoordinateSize = 32U;

    // This is a valid P-256 public key.
    static const unsigned char kSpkiEc[] = {
        0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86,
        0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x08, 0x2a,
        0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03,
        0x42, 0x00, 0x04,
        0x29, 0x5d, 0x6e, 0xfe, 0x33, 0x77, 0x26, 0xea,
        0x5b, 0xa4, 0xe6, 0x1b, 0x34, 0x6e, 0x7b, 0xa0,
        0xa3, 0x8f, 0x33, 0x49, 0xa0, 0x9c, 0xae, 0x98,
        0xbd, 0x46, 0x0d, 0xf6, 0xd4, 0x5a, 0xdc, 0x8a,
        0x1f, 0x8a, 0xb2, 0x20, 0x51, 0xb7, 0xd2, 0x87,
        0x0d, 0x53, 0x7e, 0x5d, 0x94, 0xa3, 0xe0, 0x34,
        0x16, 0xa1, 0xcc, 0x10, 0x48, 0xcd, 0x70, 0x9c,
        0x05, 0xd3, 0xd2, 0xca, 0xdf, 0x44, 0x2f, 0xf4
    };

    // This is a P-256 public key with a leading 0.
    static const unsigned char kSpkiEcWithLeadingZero[] = {
        0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86,
        0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x08, 0x2a,
        0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03,
        0x42, 0x00, 0x04,
        0x00, 0x8e, 0xd5, 0x49, 0x51, 0xad, 0x7d, 0xd3,
        0x3a, 0x59, 0x86, 0xd1, 0x2c, 0xba, 0x05, 0xd3,
        0xa6, 0x3c, 0x5d, 0x6d, 0x28, 0xde, 0x8f, 0xdd,
        0xa5, 0x3d, 0x30, 0x18, 0x05, 0x86, 0x76, 0x9c,
        0x7c, 0xa7, 0xba, 0x58, 0xea, 0x1a, 0x84, 0x19,
        0x29, 0x0a, 0x15, 0x30, 0x7d, 0x6b, 0x00, 0x41,
        0x64, 0x56, 0x84, 0x19, 0x54, 0x3e, 0x26, 0x13,
        0xc9, 0x1e, 0x31, 0x89, 0xe2, 0x62, 0xcb, 0x3f
    };

    // Section 2 of RFC 7515 defines that an URL-safe base64 encoding must be used
    // with all trailing '=' characters omitted. Returns whether the |input|
    // contains any of the forbidden base64 characters (+, -, =).
    bool ContainsNonUrlSafeBase64Characters(base::StringPiece input)
    {
        return input.find_first_of("+-=") != std::string::npos;
    }

} // namespace

TEST(JwkSerializerTest, ConvertSpkiFromDerToJwkEc)
{
    base::StringPiece spki;
    base::DictionaryValue public_key_jwk;

    EXPECT_FALSE(JwkSerializer::ConvertSpkiFromDerToJwk(spki, &public_key_jwk));
    EXPECT_TRUE(public_key_jwk.empty());

    // Test the result of a "normal" point on this curve.
    spki.set(reinterpret_cast<const char*>(kSpkiEc), sizeof(kSpkiEc));
    EXPECT_TRUE(JwkSerializer::ConvertSpkiFromDerToJwk(spki, &public_key_jwk));

    std::string string_value;
    EXPECT_TRUE(public_key_jwk.GetString("kty", &string_value));
    EXPECT_STREQ("EC", string_value.c_str());
    EXPECT_TRUE(public_key_jwk.GetString("crv", &string_value));
    EXPECT_STREQ("P-256", string_value.c_str());

    EXPECT_TRUE(public_key_jwk.GetString("x", &string_value));
    EXPECT_FALSE(ContainsNonUrlSafeBase64Characters(string_value));
    std::string decoded_coordinate;
    EXPECT_TRUE(base::Base64UrlDecode(
        string_value, base::Base64UrlDecodePolicy::DISALLOW_PADDING,
        &decoded_coordinate));
    EXPECT_EQ(kEcCoordinateSize, decoded_coordinate.size());
    EXPECT_EQ(0,
        memcmp(decoded_coordinate.data(),
            kSpkiEc + sizeof(kP256SpkiPrefix),
            kEcCoordinateSize));

    EXPECT_TRUE(public_key_jwk.GetString("y", &string_value));
    EXPECT_FALSE(ContainsNonUrlSafeBase64Characters(string_value));
    EXPECT_TRUE(base::Base64UrlDecode(
        string_value, base::Base64UrlDecodePolicy::DISALLOW_PADDING,
        &decoded_coordinate));
    EXPECT_EQ(kEcCoordinateSize, decoded_coordinate.size());
    EXPECT_EQ(0,
        memcmp(decoded_coordinate.data(),
            kSpkiEc + sizeof(kP256SpkiPrefix) + kEcCoordinateSize,
            kEcCoordinateSize));

    // Test the result of a corner case: leading 0s in the x, y coordinates are
    // not trimmed, but the point is fixed-length encoded.
    spki.set(reinterpret_cast<const char*>(kSpkiEcWithLeadingZero),
        sizeof(kSpkiEcWithLeadingZero));
    EXPECT_TRUE(JwkSerializer::ConvertSpkiFromDerToJwk(spki, &public_key_jwk));

    EXPECT_TRUE(public_key_jwk.GetString("kty", &string_value));
    EXPECT_STREQ("EC", string_value.c_str());
    EXPECT_TRUE(public_key_jwk.GetString("crv", &string_value));
    EXPECT_STREQ("P-256", string_value.c_str());

    EXPECT_TRUE(public_key_jwk.GetString("x", &string_value));
    EXPECT_FALSE(ContainsNonUrlSafeBase64Characters(string_value));
    EXPECT_TRUE(base::Base64UrlDecode(
        string_value, base::Base64UrlDecodePolicy::DISALLOW_PADDING,
        &decoded_coordinate));
    EXPECT_EQ(kEcCoordinateSize, decoded_coordinate.size());
    EXPECT_EQ(0,
        memcmp(decoded_coordinate.data(),
            kSpkiEcWithLeadingZero + sizeof(kP256SpkiPrefix),
            kEcCoordinateSize));

    EXPECT_TRUE(public_key_jwk.GetString("y", &string_value));
    EXPECT_FALSE(ContainsNonUrlSafeBase64Characters(string_value));
    EXPECT_TRUE(base::Base64UrlDecode(
        string_value, base::Base64UrlDecodePolicy::DISALLOW_PADDING,
        &decoded_coordinate));
    EXPECT_EQ(kEcCoordinateSize, decoded_coordinate.size());
    EXPECT_EQ(0, memcmp(decoded_coordinate.data(), kSpkiEcWithLeadingZero + sizeof(kP256SpkiPrefix) + kEcCoordinateSize, kEcCoordinateSize));
}

} // namespace net
